• Gets your comments on /r/churning from the past 3 months. Reddit only gives the last 1000 comments total so if you are a very active user, this might not be accurate
• For each of your comments, check the comment score
• If comment score>0, add (comment score-1). Otherwise the comment does not add anything to your churning karma.

Everything is fetched locally by your browser so don't abuse this by checking everyone's score. Doing so might cause reddit to place limits on you.